Re: [fluka-discuss]: user biasing using usimbs.f *** Doeimb: importance splitting not performed for missing room, in Emf stack ***

From: Mina Nozar <nozarm_at_triumf.ca>
Date: Mon, 27 Apr 2015 12:43:10 -0700

Hi Vittorio,

1) The manual says nothing about the settings for WHAT(2) and WHAT(3) of
the Biasing card, if SDUM is set to USER other than.

*"If SDUM = USER, setting WHAT(3) = 1. for a region will suppress all
calls to routine USIMBS during tracking inside that region.*"

Logic tells me if one does not wish to bias a region, then
a) do not have a Biasing card defined for that region
or
b) use a biasing card with SDUM = USER but set WHAT(2) and WHAT(3) to 1.


So why just not define a biasing card for that region???


2) The last advanced course slide on Simulation Optimization, page 22
says " WHAT(2) and WHAT(3) (Any value not equal to 1).
That is, if one wishes to call usimbs via SDUM is set to USER in the
Biasing card. That is exactly what I have done. Setting WHAT(2) and
WHAT(3) to 2.
So Setting WHAT(2) and WHAT(3) to 2 does not mean I have set the
importance and RR ratios to 2 for those regions. The importance ratio
is determined via usimbs.f.


Mina





All your region have *importance* 2 and *RR ratio* 2.

On 15-04-25 02:35 AM, Vittorio Boccone wrote:
>
> Hi Mina,
>
> sorry for the previous mail. I see that the meaning of my previous
> message was heavily affected by the automatic corrector.
>
> It would be nice to see your custom routing as well as the input.
>
> All your region have *importance* 2 and *RR ratio* 2.
>
> If all the regions have the same importance nothing will change.
> Vittorio
> On Apr 24, 2015 4:20 AM, "Mina Nozar" <nozarm_at_triumf.ca
> <mailto:nozarm_at_triumf.ca>> wrote:
>
> >
> > Hi Vittorio,
> >
> > I am sorry, I don't understand your message.
> >
> > Do you mean you think I might be doing splitting and RR at the same
> time? How could this be?
> >
> > From the advanced course slides, I see:
> > "The Russian Roulette / Splitting will take place at the middle
> (defined by the ENTRY) of the step. "
> >
> > The same routine seems to be working for the proton beam on the
> target. So it is an issue with the electron beam. But I don't know
> how to go about investigating this. Can one of the experts/developers
> help please? I am stuck.
> >
> > Thank you,
> > Mina
> >
> >
> > On 15-04-23 01:45 PM, Vittorio Boccone wrote:
> >>
> >> HI Mina,
> >> I see you might Importance biasing and RR.
> >> Beware that the Russian Roulette massacre happens in the middle
> (defined by the ENTRY) of the steps, and not o
> >> It would be nice to see your custom usimbs.f
> >>
> >> Best,
> >> Vittorio
> >>
> >> On Thu, Apr 23, 2015 at 2:37 AM, Mina Nozar <nozarm_at_triumf.ca
> <mailto:nozarm_at_triumf.ca>> wrote:
> >>>
> >>> Thanks Mario.
> >>>
> >>> But I don't think I have been too aggressive in the biasing.
> >>>
> >>> I start biasing 1 meter from the center of the target (RMIN = 100
> cm) and bias by a factor of 2 every 35 cm (RINC) until R = 800 cm
> (RMAX). See attached image. This is what I print in the output file
> (for lfirst).
> >>>
> >>> ***** usimbs CALLED *****
> >>> AETE_Cx -1278.
> >>> AETE_Cy 8183.88
> >>> AETE_Cz 5948.
> >>> DMIN_IMP 0.0001
> >>> RMIN 100.
> >>> RMAX 800.
> >>> RINC 35.
> >>> 1 99999 99999 0.0000000E+00
> 1.0000000E+30 0
> >>> NEXT SEEDS: E9 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 2000 98000 98000 5.6441402E-04
> 1.0000000E+30 133
> >>> NEXT SEEDS: 2C8E4A 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 4000 96000 96000 5.5066633E-04
> 1.0000000E+30 255
> >>> NEXT SEEDS: 57629D 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> ...
> >>> ...
> >>>
> >>> In the .err file, I see:
> >>>
> >>>
> >>> NEXT SEEDS: 0 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 1 99999 99999 0.0000000E+00
> 1.0000000E+30 0
> >>> NEXT SEEDS: E9 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 2000 98000 98000 5.7591248E-04
> 1.0000000E+30 133
> >>> NEXT SEEDS: 2C8E4A 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 4000 96000 96000 5.6066513E-04
> 1.0000000E+30 255
> >>> NEXT SEEDS: 57629D 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 6000 94000 94000 5.9057713E-04
> 1.0000000E+30 409
> >>> NEXT SEEDS: 8987D8 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 8000 92000 92000 5.9815907E-04
> 1.0000000E+30 530
> >>> NEXT SEEDS: B9BD7F 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 10000 90000 90000 6.0090866E-04
> 1.0000000E+30 666
> >>> NEXT SEEDS: E9782F 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 12000 88000 88000 6.2340530E-04
> 1.0000000E+30 808
> >>> NEXT SEEDS: 120B7BB 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 14000 86000 86000 6.2054852E-04
> 1.0000000E+30 939
> >>> NEXT SEEDS: 14F66E4 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> 16000 84000 84000 6.1765611E-04
> 1.0000000E+30 1058
> >>> NEXT SEEDS: 17DC3F2 0 0 0 0 0 C6AD
> 2A4C 0 0
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> in Emf stack ***
> >>> *** Doeimb: importance splitting not performed for missing room
> >>> ...
> >>> ...
> >>>
> >>>
> >>> Thanks,
> >>> Mina
> >>>
> >>>
> >>>
> >>> On 15-04-22 02:31 PM, Santana, Mario wrote:
> >>>>
> >>>> From the message, and given that you were setting importances via
> usimbs.f, it seems that you have gone too aggressive in the biasing
> and you have filled the emf stack.
> >>>>
> >>>> This means that you set a step biasing split that was much bigger
> than the attenuation for your electrons and photons through your
> shielding. As a result, the population of electrons and photons was
> growing larger every step, and you filled the memory.
> >>>>
> >>>> Reduce the parameter by which you bias. Normally you would want
> to set that parameter so that the population of your particles of
> interest stays more or less constant.
> >>>>
> >>>> - Mario
> >>>>
> >>>> From: Mina Nozar <nozarm_at_triumf.ca <mailto:nozarm_at_triumf.ca>>
> >>>> Date: Wednesday, April 22, 2015 12:36 PM
> >>>> To: fluka-discuss <fluka-discuss_at_fluka.org
> <mailto:fluka-discuss_at_fluka.org>>
> >>>> Subject: [fluka-discuss]: user biasing using usimbs.f *** Doeimb:
> importance splitting not performed for missing room, in Emf stack ***
> >>>>
> >>>> Hello everyone,
> >>>>
> >>>> I have been trying to do biasing via usimbs.f. It has taken me
> few days of trial and error. I think I have fixed few issues (one of
> which resulted in a core dump).
> >>>>
> >>>> Now, I am seeing the following message repeated ad nauseam in the
> .err file. What does this message mean and how can I go about fixing it?
> >>>>
> >>>>
> >>>> *** Doeimb: importance splitting not performed for missing room
> >>>> in Emf stack ***
> >>>>
> >>>>
> >>>>
> >>>> Thanks in advance,
> >>>> Mina
> >>>
> >>>
> >>
> >
>



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Received on Mon Apr 27 2015 - 23:12:25 CEST

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